Filter



A Dec. 8, 1936. A J. w. Frrz GERALD A 2,063,086'

FILTER F i1e1.Aug. 9, 1955 Patented Dec. 8, 1936 UNITED STATES PATENT oFFlcE Brisas & Stratton Corporation,

Milwaukee,

Wis., a corporation of Delaware Application August 9, 1935, Serial No. 35,503

2 Claims.

ticularly defined by the appended claims, it be ing understood that such changes in the precise embodiment of theA hereindisclosed invention may be made as come within the scope of the claims.

The accompanying drawing illustrates two complete examples of the physicalembodiment of the invention constructed according to the best modes soV far devised for the practical application of 'the principles thereof, and in which:

Figure 1 is a longitudinal section view through a lter unit embodying this invention; Y

Figure 2 is a greatly magnified cross section view through a portion of the lter unitper se; and

Figure 3 illustrates a portion of a filter unit of slightly modied construction.

Referring now more particularly to the accompanying drawing, the numeral 5 designates the casing of the filter unit, which, as is customary, is provided with vinlet and outlet nipples 6 and 1, respectively. The inlet and outlet nipples are connectible with the pressure lubricating system of an internal combustion engine in the conventional manner so as to conduct lubricant under pressure into the interior of the casing and to return ltered lubricant back into the System.

Attached to the outlet nipple 1 and extending down into the interior of the casing 5 is a hollow perforated core 8.' Surrounding this core and tied thereto as at 9 is a bag i0. The bag I0 is of a size to illl the major portion of the interior of the casing 5 and may be composed of lordinary cloth, or as shown in Figure' 3, may have its wall composed of outer and inner cloth layers il and I2respectively, with a layer of iilter paper I3 disposed therebetween.

'I'he bag isloosely filled with a suitable loose finelydivided material Il which has a degree of natural resiliency, and 'an ability to lter lubricant passed therethrough. Ordinary sawdust has been found to be very well suited to the (Cl. -Zul- 131) purpose of this invention although other materials such as looselycarded animal wool, cotton waste, ground cork, and similar materials, may be employed with good results.

To prevent 'the passage of the bag contents 5 I4 through the perforations I5 in the hollow core, a screen i6 surrounds the core.

As stated, the bag is but loosely filled and its contents have a degree of natural resilience so that fluid pressure within the casing 5, more or 10 less collapses and deforms the bag, from its normal shape depicted in dotted lines in Figure 1, to a compressed state shown in full lines. Upon reduction in the fluid pressure within the casing 5, the expansion of the bag contents because of its natural resilience causes internal motion of the bag contents and continuously rearranges the particles thereof and presents an ever changing relationship between the wall oi the bag and its contents so that the filter unit by its own inherent action is kept from clogging.

Tests have shown that the performance of the filter of this invention equals and exceeds that of filters heretofore in use regardless, of their cost. No irrefutable or conclusive explanation of how the construction here presented gains its advantage over past filters has been established, but it is believed that the success of the unit is due primarily to the fact that under compression the inner surface of the bag wall is forced into close juxtaposition with the bag contents so that through the coaction of the wall ofthe bag and the outer layer of its contents, ltering inter'- stices -are provided which otherwise would not be present. 3

The performance of the unit is improved through the use of a multiple layer wall for the bag such as illustrated in Figure 3, but the advantages of this multiple layer construction over the single layer are not so pronounced as to indio cate that the primary filtering action is obtained by the wall of the bag per se; and tests with different materials in the bag indicate that the effectiveness of the unit is not dependent upon the nature of the bag contents.

But tests with constructions using only the loose material, even though it is held about a' perforated core by means of an open mesh screen or the like, show a marked reduction in effectiveness. 50

From these tests, the theory suggested hereinbefore has been deduced, namely, 4that a novel y coaction exists between the bag wall and its contents upon compression of the unit to provide filu tering interstlces which otherwise are not 'present; and that'the constant' internal motion resulting from variations in the fluid pressure on the bag keeps rearranging the particles' oi' the bag contents and prevents clogging.

From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art to which this invention appertains, that this invention provides a illter unit of exceptionally simple and inexpensive construction.

What I claim as my invention is:

1. A filter device connectible with a pressure lubricating system ot an internal combustion engine and comprising a casing having an inlet conneetible with the lubricating system to receive lubricant under pressure and an outlet for filtered lubricant, a hollow perforated core'connected with the outlet and disposed wholly within the casing, and a cloth bag enclosing theperforated portion of the core and containing a quantity of sawdust, said sawdust being loosely packedin the bag so that the bag is readily deformed and its sawdust contents placed in compression by iluid pressure within the casing to expand upon a reductionv in the uld pressure within the casing and thereby 'produce internal motion within I agoeaoae the contents ofy the bag upon each variation of fluid pressure.

2. A filter device connectible with a pressurelubricating system of an internal combustion engine and comprising a casing having an inlet connectible with the lubricatingsystem to receive lubricant under pressure and an outlet for ltered lubricant, a hollow perforated core connected with the outlet and disposed wholly within the casing, a fabric bag disposed within the casing with the perforated portion of the core inside the bag, and loose material filling the bag around the perforated core, said material being capable of a filtering action and being inherently resilient and loosely packed in the bag so that the bag is readily deformed and its contents placed in compression by lubricant introduced into the casing under pressure and passing through the ,bag contents to the perforated core, and whereby iluctuations in iluid pressure within the casing results -in expansion and contraetion of the bag contents dueto its inherent resiliency to cause internal motion of the bag con- -tents so that dierent portions of the bag con-v tents are constantly presented to the inside surface of the bag. v

JOHN W. FI'IZ GERALD. 

